Manipulation of Liquid Metal Inside an SEM by Taking Advantage of Electromigration

We present a new technique to produce liquid metal spheres with customized diameters using electromigration. The liquid metal used is a versatile material, which is increasingly implemented in micromanipulation applications. The theories of mass transport activated by electromigration are compared with experimental results. The knowledge gained from the theory is used to optimize this method. Therefore, different tip designs with at constant current are used. The measurement results are presented to characterize the mass flow depending on a certain current density. These results show a direct correlation between the current applied and the mass flow of the liquid metal, as assumed by theory. At the end, a successful pick-and-place application with the investigated process is presented. This application will in future simplify the manipulation and the analysis of liquid metals on the small scale.